Dreaded 18's

[stew]

Hi All

Ever since putting my 18's on my LS, i have a series of problems...

first of all they rubbed on the plastic inner arches, that was sorted.

But now when the car is fully laden it seems to ground at the rear, all the time.

Initially, it was all at the front, so i dropped the front's tyre profile, that sorted that!

but now it's all at the back. I did post a topic on shocks, but i need to know, whether, it's simply the wheel size (and everyone gets this, when they uprate their wheels), or i need to look at new springs and shocks?

Cheers Stew

[Brettster]

I would have thought that putting bigger wheels on your car would make the car higher off the ground

is it the bottom of the car thats hitting the ground? or the arches hitting the wheels?

[GreyBeard]

must be tyres on wheel arch liners, or wheels on calipers, or something. can't you load it up, then feel around tyres and wheels?

[stew]

Yeah, thats worth a try, it s definitely not the calipers

Stew

[chips229]

Hi,what do you mean by ground at the back?

My car sits high at the back,can you say measure how high your car is sat on the back,say from the bottom of the bumper lip to the ground,and i will measure the ride height of mine at the back tomorrow,if your rear ride height is low then the springs could be getting tired.Ive found my car with shopping and people in the back easy to bottom out.Ive 18s on my 400,do you have the same size tyres front and back or wider on the back?

Im running the same size tyres all round and have no tyre rub on the back.

Whats the off set of your wheels stew?

If you have 235/40/18 then the ride height of the car should be the same as standard.At a guess id say your springs are tired.

What tyre pressures are you running stew?

[stew]

My car tends to sit high at the back anyway (look at pics in "the garage")...At the moment i'm running 245/45/18's on the rears, and 245/40/18's on the front with pressures at about 38psi..

I think i tend to agree, that the springs are knackered, but fear the cost of replacing them and the shocks....ouch!

Stew

[LennyLexus]

My car tends to sit high at the back anyway (look at pics in "the garage")...At the moment i'm running 245/45/18's on the rears, and 245/40/18's on the front with pressures at about 38psi..

I think i tend to agree, that the springs are knackered, but fear the cost of replacing them and the shocks....ouch!

Stew

time for a set of coilovers ;)

[andy haw]

tyre pressure looks to be to high,would suggest around about 31/32.

[chips229]

Ive found since switching from ballon tyres 205/65/15s on the Senator24V to

235/40s i think/17s,and now 205/65/15 to 245/40/18s on the 400,because of the squarer shape of the lower profiles tyres (40s etc) and id say they ride flatter on the road,meaning theres more tyre to road contact i also tend to run a high tyre pressure like stew.In the fronts i have 42 in both the Senator and LS 400 which is the max which it says on the tyre and rears 36 on both cars.Ive found on the senator they wore evenly across the tyre fronts and backs,not had the tyres on the 400 long enough yet to see much wear...

my point is,im no tyre expect but id say the low profile 35s,40s,etc need a higher pressure so they dont roll on the wall of tyre and the distance from rim to road is less so theres less tyre bounce.

[flotsam]

The weight of the wheel assembly is carefully calculated to avoid resonance problems etc. It can be dangerous if at certain speeds the wheel is not in contact with the road for too long and is just bobbing about for example.

Frankly it sounds as though you've made a mess of things. You can't just go and swap wheels without even worrying about the clearance in the wheel arches.

[chips229]

Ive spent weeks finding out about what wheels will fit the LS400 and there are very few that fit straight out the box,the off set needs to be at least 41 or more 45 is good or they will rub on the arches,the higher the offset the nearer the wheels are to the middle of the car...giving clearance...for the arch.. :)